[compiler-rt] r292630 - [scudo] Replacing std::atomic with Sanitizer's atomics

Kostya Kortchinsky via llvm-commits llvm-commits at lists.llvm.org
Fri Jan 20 10:32:19 PST 2017


Author: cryptoad
Date: Fri Jan 20 12:32:18 2017
New Revision: 292630

URL: http://llvm.org/viewvc/llvm-project?rev=292630&view=rev
Log:
[scudo] Replacing std::atomic with Sanitizer's atomics

Summary:
In an effort to getting rid of dependencies to external libraries, we are
replacing atomic PackedHeader use of std::atomic with Sanitizer's
atomic_uint64_t, which allows us to avoid -latomic.

Reviewers: kcc, phosek, alekseyshl

Reviewed By: alekseyshl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28864

Modified:
    compiler-rt/trunk/lib/scudo/scudo_allocator.cpp
    compiler-rt/trunk/lib/scudo/scudo_allocator.h
    compiler-rt/trunk/test/scudo/interface.cpp
    compiler-rt/trunk/test/scudo/lit.cfg
    compiler-rt/trunk/test/scudo/malloc.cpp
    compiler-rt/trunk/test/scudo/realloc.cpp

Modified: compiler-rt/trunk/lib/scudo/scudo_allocator.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/scudo/scudo_allocator.cpp?rev=292630&r1=292629&r2=292630&view=diff
==============================================================================
--- compiler-rt/trunk/lib/scudo/scudo_allocator.cpp (original)
+++ compiler-rt/trunk/lib/scudo/scudo_allocator.cpp Fri Jan 20 12:32:18 2017
@@ -125,8 +125,7 @@ struct ScudoChunk : UnpackedHeader {
     UnpackedHeader NewUnpackedHeader;
     const AtomicPackedHeader *AtomicHeader =
         reinterpret_cast<const AtomicPackedHeader *>(this);
-    PackedHeader NewPackedHeader =
-        AtomicHeader->load(std::memory_order_relaxed);
+    PackedHeader NewPackedHeader = atomic_load_relaxed(AtomicHeader);
     NewUnpackedHeader = bit_cast<UnpackedHeader>(NewPackedHeader);
     return (NewUnpackedHeader.Checksum == computeChecksum(&NewUnpackedHeader));
   }
@@ -135,8 +134,7 @@ struct ScudoChunk : UnpackedHeader {
   void loadHeader(UnpackedHeader *NewUnpackedHeader) const {
     const AtomicPackedHeader *AtomicHeader =
         reinterpret_cast<const AtomicPackedHeader *>(this);
-    PackedHeader NewPackedHeader =
-        AtomicHeader->load(std::memory_order_relaxed);
+    PackedHeader NewPackedHeader = atomic_load_relaxed(AtomicHeader);
     *NewUnpackedHeader = bit_cast<UnpackedHeader>(NewPackedHeader);
     if (NewUnpackedHeader->Checksum != computeChecksum(NewUnpackedHeader)) {
       dieWithMessage("ERROR: corrupted chunk header at address %p\n", this);
@@ -149,7 +147,7 @@ struct ScudoChunk : UnpackedHeader {
     PackedHeader NewPackedHeader = bit_cast<PackedHeader>(*NewUnpackedHeader);
     AtomicPackedHeader *AtomicHeader =
         reinterpret_cast<AtomicPackedHeader *>(this);
-    AtomicHeader->store(NewPackedHeader, std::memory_order_relaxed);
+    atomic_store_relaxed(AtomicHeader, NewPackedHeader);
   }
 
   // Packs and stores the header, computing the checksum in the process. We
@@ -162,10 +160,10 @@ struct ScudoChunk : UnpackedHeader {
     PackedHeader OldPackedHeader = bit_cast<PackedHeader>(*OldUnpackedHeader);
     AtomicPackedHeader *AtomicHeader =
         reinterpret_cast<AtomicPackedHeader *>(this);
-    if (!AtomicHeader->compare_exchange_strong(OldPackedHeader,
-                                               NewPackedHeader,
-                                               std::memory_order_relaxed,
-                                               std::memory_order_relaxed)) {
+    if (!atomic_compare_exchange_strong(AtomicHeader,
+                                        &OldPackedHeader,
+                                        NewPackedHeader,
+                                        memory_order_relaxed)) {
       dieWithMessage("ERROR: race on chunk header at address %p\n", this);
     }
   }

Modified: compiler-rt/trunk/lib/scudo/scudo_allocator.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/scudo/scudo_allocator.h?rev=292630&r1=292629&r2=292630&view=diff
==============================================================================
--- compiler-rt/trunk/lib/scudo/scudo_allocator.h (original)
+++ compiler-rt/trunk/lib/scudo/scudo_allocator.h Fri Jan 20 12:32:18 2017
@@ -22,8 +22,6 @@
 # error "The Scudo hardened allocator is currently only supported on Linux."
 #endif
 
-#include <atomic>
-
 namespace __scudo {
 
 enum AllocType : u8 {
@@ -58,7 +56,7 @@ struct UnpackedHeader {
   u64 Salt        : 8;
 };
 
-typedef std::atomic<PackedHeader> AtomicPackedHeader;
+typedef atomic_uint64_t AtomicPackedHeader;
 COMPILER_CHECK(sizeof(UnpackedHeader) == sizeof(PackedHeader));
 
 // Minimum alignment of 8 bytes for 32-bit, 16 for 64-bit

Modified: compiler-rt/trunk/test/scudo/interface.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/scudo/interface.cpp?rev=292630&r1=292629&r2=292630&view=diff
==============================================================================
--- compiler-rt/trunk/test/scudo/interface.cpp (original)
+++ compiler-rt/trunk/test/scudo/interface.cpp Fri Jan 20 12:32:18 2017
@@ -1,4 +1,4 @@
-// RUN: %clang_scudo %s -o %t
+// RUN: %clang_scudo %s -lstdc++ -o %t
 // RUN: %run %t 2>&1
 
 // Tests that the sanitizer interface functions behave appropriately.

Modified: compiler-rt/trunk/test/scudo/lit.cfg
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/scudo/lit.cfg?rev=292630&r1=292629&r2=292630&view=diff
==============================================================================
--- compiler-rt/trunk/test/scudo/lit.cfg (original)
+++ compiler-rt/trunk/test/scudo/lit.cfg Fri Jan 20 12:32:18 2017
@@ -19,9 +19,7 @@ config.suffixes = ['.c', '.cc', '.cpp']
 # C flags.
 c_flags = ([config.target_cflags] +
            ["-std=c++11",
-           "-lstdc++",
            "-lrt",
-           "-latomic",
            "-ldl",
            "-pthread",
            "-fPIE",

Modified: compiler-rt/trunk/test/scudo/malloc.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/scudo/malloc.cpp?rev=292630&r1=292629&r2=292630&view=diff
==============================================================================
--- compiler-rt/trunk/test/scudo/malloc.cpp (original)
+++ compiler-rt/trunk/test/scudo/malloc.cpp Fri Jan 20 12:32:18 2017
@@ -1,4 +1,4 @@
-// RUN: %clang_scudo %s -o %t
+// RUN: %clang_scudo %s -lstdc++ -o %t
 // RUN: %run %t 2>&1
 
 // Tests that a regular workflow of allocation, memory fill and free works as

Modified: compiler-rt/trunk/test/scudo/realloc.cpp
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/scudo/realloc.cpp?rev=292630&r1=292629&r2=292630&view=diff
==============================================================================
--- compiler-rt/trunk/test/scudo/realloc.cpp (original)
+++ compiler-rt/trunk/test/scudo/realloc.cpp Fri Jan 20 12:32:18 2017
@@ -1,4 +1,4 @@
-// RUN: %clang_scudo %s -o %t
+// RUN: %clang_scudo %s -lstdc++ -o %t
 // RUN:     %run %t pointers 2>&1
 // RUN:     %run %t contents 2>&1
 // RUN: not %run %t memalign 2>&1 | FileCheck %s




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